The phrase “military advisers” always carries with it a grim historic resonance for those who remember the Vietnam War. It was a small contingent of military advisers that became the advance guard of a military intervention that involved hundreds of thousands of U.S. troops and a disastrous war.

Thus, President Barack Obama’s announcement Thursday that he would send a contingent of 300 special forces to Iraq as military advisers might ring alarm bells. The difference is that we’ve already had our war with Iraq, and Obama has built his political career on his belief that the war was a mistake. He made clear that U.S. combat troops were not heading back to Iraq. The political and military disintegration now under way in Iraq will have to be sorted out by Iraqis. But they will have U.S. help.

Presumably, Obama is sending special forces back to Iraq because he believes they will have useful help to offer the Iraqi government as it recovers from the sudden advance of a jihadi insurgent force. He made clear that the Iraqi government must also get its act together, and there were suggestions in the press that the United States will be pressing behind the scenes for the replacement of Iraqi Prime Minister Nouri al-Maliki.

It is disappointing that Iraq under al-Maliki has not been able to rise above the sectarian divisions that were exacerbated during the civil war between Sunni and Shia in 2006 and 2007. It is disappointing that those divisions have created an opening for ISIS, the vicious terrorist group that is operating out of Syria and bringing its medieval methods to Iraq. It is disappointing, too, that the United States, even a force of only 300, must return to Iraq to help avert a worsening situation.

It is a mistake, however, to believe that the United States is not already involved in Iraq, despite the departure in 2011 of the last of the U.S. military presence. The United States does not instantly become Switzerland just because it has pulled out its troops. The United States has an interest in promoting stability in the region, partly because the power and influence that we wield remains considerable and not using it in a positive fashion leaves a vacuum that can lead to havoc threatening our allies in the region — Israel, Jordan, Turkey — as well as the economic well-being of the world. We also have an interest in improving ties with Iran. Absenting ourself from the field does not further any of these goals.

Presumably, the 300-person contingent of special operations forces will help the Iraqi military, and potentially U.S. air forces, including drones, target ISIS fighters. Presumably also, a reconstituted Iraqi government, galvanized by the latest crisis, will see the need for Sunni tribes, Shia forces and Kurds to band together to combat extremists. Apparently, Obama sees the present crisis as a back-door entry to Syria, leaving open the option of targeting ISIS forces there. Until now the Syrian civil war did not threaten U.S. interests directly enough to warrant significant intervention, in Obama’s view. With the threat to Iraq, that is changing.

The Monday morning quarterbacking contributed by the likes of Dick Cheney and Paul Bremer about the latest Iraq crisis is a revolting spasm of self-justification, distortion and the usual lies. Criticism from politicians such as Sen. John McCain represents a mindless and reflexive faith in military might long ago proven to be dangerously delusional. Obama is exercising a carefully calibrated and realistic response to a difficult situation that, as much as he might like to do, he cannot ignore.